1. Field of Invention
The present invention relates to a racket and more particularly, to a racket such as a tennis racket a badminton racket, except for the handle, having an ovoid cross section when taken in a plane orthogonal to an axis of a segment of the head.
2. Related Prior Art
A known racket is disclosed in U.S. Pat. No. 5,076,583 entitled as "Racket frame with circular cross section and variable thickness", filed on Aug. 21, 1990 to Henry Hsu, the racket including a head portion, a throat portion, a bridge and a handle portion, the frame of the head portion in accordance with the above mentioned patent has a circular cross section which diameter can be varied such as shown in FIGS. 1 through 5 of the patent so as to has an improved aerodynamic feature and hitting response. In fact, the circular cross section has a larger air resistance area than that of an elliptical cross section as shown in FIGS. 1 and 2 of another type of tennis racket, the frame 11 of the head portion 10 of the latter racket has a narrower surface when viewed orthogonal to a string area 12 of the racket, but the racket shown in FIGS. 1 and 2 has a larger drop "D" measured from the string area 12 to each distal end of the cross section of the frame 11, therefore, when a ball 13, shown in phantom lines, is stricken on the abutment of the frame 11 and the string area 12 of the head portion 10 as shown in FIG. 2, the response trajectory of the ball 13 is directly affected by the frame 11 rather than the string area 12 when the head portion 10 has a larger drop "D", on the other hand, the effective striking area of this kind of racket is reduced. Therefore, neither the racket disclosed in U.S. Pat. No. 5,076,583 nor the racket shown in FIGS. 1 and 2 can provide a racket which has a low air resistance area and a larger effective striking area.
The present invention intends to provide a racket which head has an ovoid cross section, except for the handle, when taken in a plane orthogonal to an axis of the segment of the frame wherein the ovoid cross section includes a front arc, a rear arc, an inner arc, an outer arc and four connecting arcs, each of the connecting arcs smoothly connected between the front arc and the inner arc, the inner arc and the rear arc, the front arc and the outer arc and, the outer arc and the rear arc so as to form the racket with suitable stiffness, less air resistance surface and a small drop measured from the string area to the rear or front arc of the frame.